package 牛客;

import java.util.Scanner;

//输入： abcqweacb
//输出： abcqwe
public class p1求输入字符串包含的字符集合 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()) {
            String str=scanner.next();//next()不能输入空格
            StringBuilder s = new StringBuilder();

            for (int i = 0; i < str.length(); i++) {
                char c=str.charAt(i);
                if (!s.toString().contains(c+"")) {
                    s.append(c);
                }
            }
            System.out.println(s);
        }
    }
}
